The present invention relates to a functional, optical-quality lens assembly incorporating a decorative hologram as an integral portion of its structure, and the methods of manufacture of said lens assembly. The integral hologram may contain one or more holographic images or information recorded on a thin-film coating of holographic recording material which is optically smooth, and does not require any small scale three dimensional surface topology to be able to provide an external observer with an apparent three dimensional view of objects, letters, patterns, etc.
This is an important distinction from previous patent literature describing three dimensional images on sunglass lenses, as in U.S. Pat. No. 4,934,792, which employ a physical deformation of an intermediate material to form the three dimensional image. In addition, the perceived depth of the image can be much greater with the holographic approach, as opposed to bas reliefs as described in U.S. Pat. No. 4,934,792.
Also of great significance to the present invention is its relation to being a fully functional, prescription-quality lens that provides high optical clarity and minimal eyestrain to the wearer, making it suitable for long-term wear under critical conditions, such as while driving or playing sports. This uniquely distinguishes this invent:ion from commonly available novelty holographic glasses, which are not suitable for use as functional ophthomalic eyeglasses, nor do they provide the light filtering abilities of the present invention, so as to eliminate undesirable illumination or transmission of reflected or transmitted light from the holographic recording material, and additionally allow for overall light filtering, as in the possible application to sunglasses.
The progression of novelty items to the state of the presently described invention is not obvious due to inherent difficulties in producing high optical quality curved lens elements incorporating a holographic recording material that provide very high optical clarity to the wearer and do not suffer from defects such as light scatter, holographic coating irregularities, and delamination. To achieve such results as to produce a high optical quality lens incorporating a hologram requires fundamental design aspects and scientific principles which cannot be solely attributed to being obvious from existing novelty items, nor as an improvement on their design, due to the multiple components required in the presently described invention to achieve the desired high optical quality resulting lens.
The present invention achieves a high optical quality through the careful selection of low scatter, high transmission holographic recording materials, careful attention to the surface curvature and surface finish of the lens elements, and the uniformity of the holographic recording material coating. In the present case, the hologram is merely a reflective decorative component, and all light filtering ability, such as to allow its use for applications such as sunglasses, is provided by other components of the design. This uniquely distinguishes this invention from other patent literature, as in U.S. Pat. No.5,103,323, which relates to the use of a holographic optical element (HOE) as the active light filtering element to block specific wavelengths of laser light.